33 research outputs found

    Studying the effect of perceptual errors on the decisions made by the investors by effectiveness of information in Tehran Stock Exchange Company

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    There are many latent factors that are effective on the decisions made by the investors. The factors that the investors are not aware of their effectiveness and make investment decisions. The main purpose of the present research is to study the perceptual factors affecting on the decision making process of the investors and the effect of information on these factors. For this aim, 385 investors of Tehran Stock Exchange Company were selected as a sample through random sampling method and the required data were gathered via the questionnaire. The accuracy of the hypothesizes was tested via a structural equation model. The results obtained from the present study show that the decision making process of the investors is affected by the representative error, overconfidence error and mood state error by 19%. Moreover, overconfidence error is affected by the degree of information by 95% and by the anonymity of the information by 10%. The mood state error is effective on information processing time by 13% and the information processing time is effective on decision making process by 24%.Keywords: Behavioral Finance, Perceptual Error, Decision making, Investmen

    Prediction of Load in Reverse Extrusion Process of Hollow Parts using Modern Artificial Intelligence Approaches

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    Extrusion is one of the important processes to manufacture and produce military and industrial components. Designing its tools is usually associated with trial and error and needs great expertise and adequate experience. Reverse extrusion process is known as one of the common processes for production of hollow parts with closed ends. The significant load required in formation of a workpiece is one of the existing constraints for the reverse extrusion process. This issue becomes rather difficult especially for the parts having thin walls since its analysis using finite element softwares is exposed to some limitations. In this regard, application of artificial intelligence for prediction of load in the reverse extrusion process will not only save time and money, but also improve quality features of the product. Based on the existing data and methods suggested for variations of punching force through the reverse extrusion process, the system is trained and then performance of the system is evaluated using the test data in this paper. Efficiency of the proposed method is also assessed via comparison with the results of others.DOI:http://dx.doi.org/10.11591/ijece.v4i3.535

    Agar alternatives for micropropagation of African violet (Saintpaulia ionantha)

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    Agar is one of the most popular solidifying agents in plant tissue culture. High price of pure grade agar and fear of over exploitation of its resources caused searching for low cost alternatives. In this study,liquid medium with cotton substratum and different combinations of starch, semolina, potato powder and agar in two steps of micropropagation (shoot induction and proliferation) were investigated. The highest frequency of regeneration was found in media containing agar (0.8%), combination of starch: semolina: potato powder (2:1:1) in 9 and 12% and combination of starch (6%) plus agar (0.4%), butmaximum shoot numbers were produced in media containing agar (0.8%), combination of starch (6%) plus agar (0.4%) and liquid medium with cotton substratum. The best shoot proliferation take place in liquid medium with cotton substratum. The results show that the combination of starch: semolina: potato powder (2:1:1) in 9% and starch (6%) plus agar (0.4 %) can be suitable alternatives for agar in regeneration stage but the shoot number is lower than agar alone. These options are very cheaper than agar. The best shoot proliferation can be done in bioreactors or liquid medium with suitable substratum like cotton.Keywords: Gelling agent, low cost, micropropagation, liquid cultur

    Effect of genotypes and culture medium on shoot regeneration and proliferation of Gerbera jamesonii

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    Gerbera jamesonii is one of the most popular cut flowers in the world and micropropagation is the commercial way for its propagation. This method allows for obtaining large amounts of healthy homogenous plants. Thus, it is necessary to establish efficient micropropagation protocols. The objective of this study was to evaluate the organogenic response of G. jamesonii, orange and pink cultivars, under in vitro culture. Different levels of N6-benzyladenine (BA) (2, 4 and 6 mg/l) and thidiazuron (TDZ) (0.2, 0.4 and 0.6 mg/l) in combination with Indole-3-acetic acid (IAA) (0 and 0.1 mg/l) in MS medium were evaluated for shoot induction. For proliferation, regenerated shoots in TDZ were subcultured in medium supplemented with 0.2, 0.4 and 0.6 mg/l TDZ, 2 mg/l BA or 2 mg/l Kin and regenerated shoots in BA were subcultured on the induction medium. In the second phase, mediums of MS, 1/2 MS, MS with 1/2 NH4NO3 and KNO3 concentration (MS-1/2N), MS with 1/2 micro and iron elements (MS-1/2MI), B5 and 1/2 B5 on shoot induction and proliferation of pink cultivar were evaluated. In order to induce rooting in the regenerated shoots, different levels of IAA (1, 2 and 3 mg/l) and 1-Naphthaleneacetic acid (NAA) (1, 2 and 3 mg/l) in combination with sucrose (30 and 40 g/l) were evaluated Maximum shoot induction, (88.8 % and 44.4 % for orange and pink cultivars, respectively) and multiplication rate (7.6 shoots/explant for orange cultivar and 1.33 shoots/explant for pink cultivar) were obtained in medium with 4 mg/l BA and 0.1 mg/l IAA. The most effective media for shoot induction and proliferation were MS-1/2N and MS, respectively. The best rate of shoot rooting in orange cultivar (4.6 roots/explants with 4.8 cm length) and pink cultivar (5.2 roots/explants with 6.2 cm length) was  obtained by using 3 mg/l IAA and 30 mg/l sucrose. The establishment of plantlets was done successfully with 92% of survival in the greenhouse.Key words: Micropropagation, organogenesis, in vitro culture, Gerbera, cut flower

    The Effect of Chalcone Isomerase Gene Silencing on Pigment Production Pathway in Petunia hybrida with RNAi Technology

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    Introduction  Flower color is one of the most significant characteristics in ornamental plant breeding. New varieties of various plants in relation to their flower color have been obtained by monitoring the expression levels of genes involved or regulating the flavonoid and anthocyanin biosynthesis pathway. Flavonoids possess significant and diverse biological functions. They are the major pigments for flowers, fruits, seeds, and leaves. They are natural products that contain a C6-C3-C6 carbon framework and are synthesized by a branched pathway that yields both colored and colorless compounds. The gene encoding chalcone isomerase (CHI) is among the genes and enzymes identified in the flavonoid pathway. This enzyme catalyzes the isomerization of naringenin chalcone into the corresponding flavanone. CHI enzyme belongs to the family of isomerases, specifically the class of intramolecular lyases. Chalcone isomerase has a core 2-layer alpha/beta structure and has attracted much attention recently due to its role in stress response and pigment production. One of the most effective methods of genetic engineering is the reduction of flower pigments by suppression of required enzymes for their biosynthesis. RNA interference (RNAi) has provided the tool for the investigation of genes involved in the production of flower color. Silencing of any gene in the anthocyanin biosynthetic pathway can result in reduced or inhibited anthocyanin production. RNAi technology is an effective gene silencing method and a powerful tool for studying gene function and development of new traits by transformation of viral RNA or hairpin RNA (hpRNA) constructs into plants. The processing of dsRNA into 21-23-nt small interfering RNAs (siRNAs), and the mediators of RNAi, triggers cognate mRNA degradation. The hpRNAi methodology simply requires a transgene construct containing an inversely-repeated sequence of the target gene flanked with a promoter and terminator which effectively function in plants.   Material and Methods  In this research, with the design and construction of chiRNAi, the transformation of the RNAi construct was carried out of Petunia plants. Potted plants of P. hybrida were grown under standard greenhouse conditions (16-17°C night temperature and 21-24°C day temperature and photoperiod 16/8 (light/dark)). The RNAi construct including the 530 bp cds of the chalcone isomerase (chi) gene and 741 bp of pdk gene as intron between chi sense and antisense were used for transient RNAi-induced silencing. The pBI121-chi530 plasmids were introduced into A. tumefaciens strain LBA4404 by electroporation method. Colonies of A. tumefaciens carrying the desired plasmid were screened by PCR with specific primers for chi gene. RNAi construct co-cultured with petunia’s leave. Samples was kept in dark condition for 3 days and then transferred to branch induction media. Samples were investigated for phenotypical changes and chi gene expression by qRT-PCR. Results and Discussion  Transgenic lines showed a reduced number of pigments and a faded flower color. So that, in purple petunia, was shown 5 phenotypical groups. These groups was indicated different levels of chi gene silencing. In pink petunia was seen two groups of phenotypical changes. In these plants, chi-RNAi construct was reduced pigment production and so, these plants had faded colors in petals. Also, the chi gene expression was reduced in all transgenic lines. Generally, the results of this research showed that RNAi can be used as an efficient method for gene silencing. The application of gene silencing can indicate the gene’s function in biosynthesis pathways of various components such as anthocyanins. In addition, the chalcone isomerase gene was identified as one of the effective genes in anthocyanin biosynthesis pathway in Petunia plants that could be involved in the production of color in these plants; hence, chi gene silencing resulted in clear phenotypic alterations in this plant.   Conclusion  In general the concentration of the target mRNA in a particular tissue could be a factor that influences silencing efficiency. At very low levels of gene expression, small amounts of the silencing target, mRNA, could be completely degraded by the RNA-induced silencing complex (RISC), whereas the presence of higher amounts of the target mRNA may result in incomplete silencing, allowing some residual functional mRNA to be translated into the corresponding protein. This research demonstrated the hpRNA construct has been successfully established for floral tissues of P. hybrida. The hpRNA construct was developed for chi-RNAi silencing of one of the key genes in the anthocyanin biosynthetic pathway in Petunia flowers. The silencing of the chi gene is a prototype for the modification of the anthocyanin biosynthetic pathway in Petunia through gene suppression. This strategy could also be useful for rapid functional analysis of other genes involved in flower development

    An acceptance model for the adoption of smart glasses technology by healthcare professionals

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    In the recent years, there has been an increase in the interest from different industries in the adoption of smart wearable devices in the light of their inevitable ubiquity. One type of these devices is the Augmented Reality Smart Glasses (ARSGs), which can have great effect in different areas through providing timely information to users. One of the industries that can significantly reap the benefits of this technology is healthcare. However, as healthcare is a very multi-dimensional industry, there is a need for a multifaceted look into the adoption and acceptance of smart glasses by health professionals. This study tends to examine the acceptance of smart glasses by healthcare professionals based on Technology Acceptance Model (TAM) as there is an imperative for empirical studies on user perceptions, attitudes, and intentions. For this purpose, five external factors are extracted from the literature and field study, being integration with information systems, external effects, hands-free feature, technological compatibility, and documentation. The model is examined by using PLS-SEM methodology. This study found documentation to have the strongest impact on intention due to the substitution of paperwork by mobile devices and facilitation of continuous documentation

    Micropropagation of Jujube (Ziziphus jujuba)

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    Introduction: Jujube (Ziziphus jujuba) is one of the most important fruit trees in Asia which has been planted from 3,000 years ago in China for medicinal purposes. Jujube belongs to the Rhamnaceae family. The Jujube fruit is used in fresh and dry forms. The fruit is full of vitamin C and has anticancer and medicinal effects. This tree can grow on salty and dry lands in Iran. Therefore, increasing the cultivation area of Jujube can be effective for soil conservation. In the last 20years, cultivation of Jujube is is considerable in Iran specially in the South Khorasan Province and 98 % of total production of Jujube in Iran belongs to this province. The low rate of seed germination and low production of shootlets are the most important problems in Jujube proliferation, so micropropagation of this plant through tissue culture was considered. Materials and methods: In this study, Cangan ecotype of Jujube was used for multiple shoot regeneration. At the end of May, apical buds of shoots were cut from mature trees of the Research Collection of Jujube at Sarbishe, Birjand, South Khorasan Province in Iran. The buds were disinfected with 70% ethanol for 1 min and 2% sodium hypoclorite for 25 min. Then the buds were rinsed with distilled water for 25 min completely. Apical buds were placed on Murashige and Skoog (MS) medium supplemented with different concentrations of BA (0.5, 1, 1.5, 2 mg/L) in combination with IBA or NAA (0, 0.1, 0.2, 0.4 mg/L). After one month, the shoots with 3-5 cm length were transferred to rooting media (1/2 MS + IBA or IAA : 0.5, 2, 5, 10 mg/L). The data were recorded after shooting and rooting and were analysed in the facorial experiment. Results and Discussion: The results of variance analysis and mean comparisons showed that there are differences between different levels of IBA and BA alone for the number of shoots and their length (

    New insights into hydrogen trapping and embrittlement in high strength aluminum alloys

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    An attractive approach to mitigate hydrogen embrittlement (HE) is to use nano-sized particles to immobilize hydrogen. However, the atomic scale relationship between different particle-matrix characteristics in aluminum alloys and the susceptibility to HE is unknown. In this study, the effects of interactions between various interfaces and hydrogen in aluminum alloys are investigated using a comprehensive multiscale experimental and simulation-based approach that includes atomic-scale observations, simulation and advanced hydrogen mapping techniques. Depending on the nature of interfaces, e.g., coherency, size, and crystal structure, some are useful for mitigating HE, others provide hydrogen to sensitive sites, and some act as crack initiation sites.Team Poulumi De
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